The goal of this project is to develop advanced magnetic resonance (MR) imaging methods for guiding high intensity focused ultrasound (FUS) in applications in the head. FUS is a promising technique for the next generation of non-invasive therapy systems. One important feature of FUS lies in its ability to apply ultrasound from outside the body, without any skin puncture or incision. The ultrasound energy can be focused to a point within the brain, with minimal heating of the intervening tissues. The significance of this project is that it would develop imaging methods that would improve the safety and efficacy of this exciting new treatment method for neurological applications. The approach of this project is to develop MR imaging methods for both improving the quality of the focus and for visualizing the location of the focus, based on the acoustic radiation force. Imaging of the acoustic radiation force with MRI is called MR-ARFI. Our specific aims are to 1) improved MR ARFI pulse sequences, 2) develop autofocusing algorithms, and 3) develop algorithms to localize the ultrasound focus. The innovation of the project is the development of an automated way to improve the ultrasound beam focus in the brain without the cost, inconvenience, and the radiation dose of a presurgical CT scan. In addition, we will improve the visualization of the focus location, without unnecessary heat deposition in sensitive structures. PUBLIC HEALTH RELEVANCE: Focused ultrasound is a promising technique for the next generation of non-invasive cancer therapy systems. The relevance of this project to public health is that it would provide improved methods for guiding focused ultrasound treatments in the brain.